BERRIEN COUNTY, Mich. -- Michigan State Police report troopers are investigating a deadly two-vehicle crash which occurred on Sept. 4 around 11:30 a.m. on US 31.

Police say the crash occurred in the northbound lanes of US 31 near Napier Avenue.

The preliminary investigation determined an SUV was traveling south in the northbound lanes when it struck a pickup truck head-on.

The SUV's driver, a 42-year-old Muskegon woman, was killed in the collision.

The pickup truck's driver, a 34-year-old Hartland man, suffered serious, but non-life-threatening injuries, and was taken to Corewell Health Hospital for treatment.

Both drivers had seatbelts on at the time of the crash.

Police say it's currently unknown if drugs or alcohol were factors in the collision.

The investigation is ongoing.